Police investigated the scene and were working to determine if the fatal shooting was a homicide, suicide or accidental shooting.

But, during the investigation, detectives came to the determination that the gunshot was self-inflicted, TPD Homicide Sgt. Dave Walker wrote in an email on February 5.

The investigation revealed that Barlow had been alone at the Walmart located at 6615 S. Memorial just minutes before her death. While at Walmart, Barlow printed several pictures and purchased stamps and an envelope, Walker wrote.

Detectives were able to locate the book of stamps with one missing, but they couldn't find the envelope or the pictures.

Through the investigation, Barlow was linked to an inmate at the Pittsburg County Jail.

Detectives intercepted that letter on Monday, February 5 at the Pittsburg County Jail and a note was discovered inside from Barlow that, "indicated her intent to take her own life."

Also inside the letter were photos of Barlow and the photos she'd printed at Walmart.

"The evidence will point to a self-inflicted gunshot wound," Walker wrote.